1
AIPMT 2015
MCQ (Single Correct Answer)
+4
-1
Change Language
A ball is thrown vertically downwards from a height of 20 m with an initial velocity v0. It collides with the ground, losses 50 percent of its energy in collision and rebounds to the same height. The initial velocity v0 is
(Take g = 10 m s$$-$$2)
A
28 m s$$-$$1
B
10 m s$$-$$1
C
14 m s$$-$$1
D
20 m s$$-$$1
2
AIPMT 2015
MCQ (Single Correct Answer)
+4
-1
Change Language
On a frictionless surface, a block of mass M moving at speed v collides elastically with another block of same mass M which is initially at rest. After collision the first block moves at an angle $$\theta $$ to its initial direction and has a speed $${v \over 3}.$$ The second block's speed after the collision is
A
$${3 \over {\sqrt 2 }}v$$
B
$${{\sqrt 3 } \over 2}v$$
C
$${{2\sqrt 2 } \over 3}v$$
D
$${3 \over 4}v$$
3
AIPMT 2015
MCQ (Single Correct Answer)
+4
-1
Change Language
Two stones of masses m and 2m are whirled in horizontal circles, the heavier one in a radius $${r \over 2}$$ and the lighter one in radius r. The tangential speed of lighter stone is n times that of the value of heavier stone when they exprience same centripetal forces. The value of n is
A
4
B
1
C
2
D
3
4
AIPMT 2015
MCQ (Single Correct Answer)
+4
-1
Change Language
If vectors $$\overrightarrow A = \cos \omega t\widehat i + \sin \omega t\widehat j$$ and $$\overrightarrow B = \cos {{\omega t} \over 2}\widehat i + \sin {{\omega t} \over 2}\widehat j$$ are functions of time, then the value of t at which they are orthogonal to each other is
A
$$t = {\pi \over \omega }$$
B
t $$=$$ 0
C
$$t = {\pi \over {4\omega }}$$
D
$$t = {\pi \over {2\omega }}$$